9 MICROBIOLOGY

  1. Investigate diversity and handling of micro-organisms

    1. Explores the diversity and nature of microorganisms

      1. Nature of micro organisms

        1. Microscopic nature of microorganisms in terms of their relative size and units of measurements.

        2. Ubiquitous nature of microorganisms

        3. High growth rate of microorganisms

        4. Morphological, nutritional and physiological diversity of microorganisms

      2. Types of microorganisms

        1. Bacteria, archaea, cyanobacteria

        2. Unicellular protista

        3. Fungi

        4. Other agents - Mollicutes (mycoplasmas and phytoplasmas), viruses, viroids and prions

      3. Nature of virus, viroids and prions as disease causing agents

 

  1. Explores some basic laboratory techniques in microbiology

    1. Methods of sterilization

      1. Physical - moist heat, dry heat, membrane filters, UV radiation

      2. Chemical - disinfectants

    2. Preparation of culture media (NA and PDA ) and inoculation with a sample of toddy/yoghurt/root nodule

    3. Staining of bacteria found in toddy or yoghurt using a simple stain

    4. Methods of sterilization of water , culture media, glassware, heat labile substances and inoculating needles

    5. Use of alcohol and other disinfectants to control microbial populations

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1 Investigate diversity and handling of micro-organisms

 

 

LESSON 1 THE DIVERSITY AND NATURE OF MICROORGANISMS

  1. Microbiology is the study of all living organisms that are too small to be visible with the naked eye.

  2. A microorganism, or microbe, is a microscopic organism, which may exist in its single-celled form or a colony of cells. 

 

 

 

 

 

 

 

 

 

 

Ubiquitous - present, appearing, or found everywhere.

Microorganisms are ubiquitous -  that is, they are present nearly everywhere.

Reading - TRUTH ABOUT YOUR DESK 

 

Ubiquitous ---  Can they Even extreme conditions ? Yes., they are called extremophile

 

 

 

 

 

 

 

Microbial diversity is truly staggering, yet all these microbes can be grouped into five major types: Viruses, Bacteria, Archaea, Fungi, and Protists. Let's look at each one in more detail.

The most common mechanism of cell replication in bacteria is a process called binary fissionFor example, Clostridium perfringens, one of the fastest-growing bacteria, has an optimum generation time of about 10 minutes; Escherichia coli can double every 20 minutes.

  1. Coccus (1)

  2. diplococcus (2),

  3. tetrad (4)

  4. sarcina (8)

  5. staphylococcus (many)

  6. Bacillus (1) ,

  7. diplobacilli (2),

  8. stphylobacilli (many)

  9. Vibrio (1),

  10. spirillum (1),

  11. spirichete (1)

 

 

 

 

 

 

 

 

 

 

Autotrophs

These are organisms that utilize CO2 as their sole source of carbon.

 

Heterotroph

These are organisms that use preformed organic substances from other organisms as their carbon sour

Based on energy source, microorganisms are classified into Phototrophs and Chemotrophs.

 

Photoautotrophs

These are organisms that utilize light and carbon dioxide to make as their energy. Purple sulfur and green sulfur bacteria  

 

 

 

 

 

 

 

 

 

 

Photoheterotrophs

These are organisms that utilize light and organic carbon to make as their energy. Purple non sulfur

 

Chemoautotrophs

These are organisms that obtain energy by inorganic carbon and crabon dioxide. Nitrobacter, Nirtorsomonas, Thiobacillus

 

Chemoheterotrophs

These are organisms that obtain energy by organic chemicals and Most bacteria

 

 

 

 

 

 

 

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LESSON 2 MICROORGANISM CLASSIFIED ON TYPE OF NUTRITION

Summary

Purple sulfur bacteria (PSB) are photosynthetic and reduce carbon dioxide to carbohydrates using hydrogen sulfide instead of water. In addition to the growth of PSB, high sulfide concentrations and high ammonia concentrations promote the growth of green sulfur bacteria. The presence of PSB typically indicates septicity, and a bloom of bacteria may contribute to high effluent total suspended solids. To control PSB in a facultative lagoon, an increase in dissolved oxygen concentration is required. Green sulfur bacteria are strict anaerobes that are capable of photosynthesis. Green sulfur bacteria absorb longer wavelengths of light than purple sulfate bacteria. Green sulfur‐reducing bacteria also occur in anaerobic, sulfate‐containing environments including wetlands and overloaded facultative lagoons. Purple and green sulfur bacteria are one of the four major groups of sulfur bacteria, and they belong in the group of phototrophic bacteria

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